I agree. He is an expert in video compression, not patent law.
I think his argument as to VP8's patent status is flawed. He claims that VP8 is likely covered by patents because it shares many features with H.264. However, I suspect that these common features are those that are covered by known patents. A list of all known H.264 patents is available on MPEG-LA's website; therefore, it is public knowledge what features of H.264 are protected by known patents. However, nobody has been able to name a specific patent that VP8 violates. On2 surely must have reviewed this list when designing VP8, and borrowed all those features of H.264 that are not covered by known patents.